This is the NHLBI portion of a program project grant jointly supported with NIAMDD and consists of three core facilities and five research projects. The core facilities are a pulmonary function laboratory, a computer center and a fiberoptic bronchoscopy center. A clinical research project is objectively evaluating the short and long term efficacy of lobar bronchopulmonary lavage in CF patients. A well-tolerated technique has been developed for lavage with relatively large volumes under topical anesthesia, even in preadolescent children. Three research projects are studying the pathophysiology of Pseudomonas pulmonary infection in CF patients. One project is assessing the ability of lymphocytes from CF patients to respond to pseudomonas and other bacterial antigens. Preliminary observations indicate the lymphocytes from some patients, particularly those whose clinical status is poor, have a diminished or absent blast response to Pseudomonas antigen while responses to other bacterial antigens are normal. Another project is studying the ability of alveolar macrophages (AM) to phagocytose and kill Pseudomonas and other bacterial organisms. Preliminary results, using a sensitive technique to quantitatively assess phagocytosis, coroborate earlier findings that CF serum selectively inhibits the rabbit AM phagocytosis of Pseudomonas organisms. An additional project is investigating antigen-specific, lymphocyte-mediated, in vitro activation of rabbit AM. Quantitative criteria of activation are being used to assess conditioned media from cultures of patient lymphocytes which have been stimulated by Pseudomonas and other bacterial antigens. The fifth research project is studying the effect of serum from CF patients on the in vitro production and release of respiratory mucous glycoproteins. An explant culture system using cat trachea has been developed in which synthesis and release of mucous glycoproteins is followed using the incorporation of 35 SO4, and 3H-glucosamine.